Thursday, December 06, 2007

Below is the last part of Mike Wiest's review of and reflections on The World as Will and Representation, Volume One. The first two parts are here and here.

Well, I guess you can tell because I wrote this that I was impressed by Schopenhauer’s book. It seems to me to belong among the greatest works of philosophy ever, and to be the first (only?) time a major Western philosopher really absorbed the Eastern insights. But I may be still in the infatuated stage.

I guess the theory of determinism and freedom I gleaned from Volume 1 is not entirely satisfactory, but I think it is more than the usual semantic sophisms that attempt to make freedom and determinism compatible. Although S comes off as mainly determinist, I think it is an open question whether his scheme could be adapted to a quantum ontology (for example if quantum events are determined by nonlocal factors scattered all over spacetime including in the future). Maybe I’m also more open to him than most determinists because he admits and explains a much greater range of phenomena, such as the claims and behavior of mystics, than hard-core 19th-century-style determinists.

I fell in love with Kant when I read his abridged Critique of Pure Reason, I think mainly because of my pet interest in quantum and mental holism, and he was constantly talking about the various unities of the mind which people seem not to appreciate anymore. But reading S gave me a perspective from which to realize that a lot of Kant really is obscure (and according to S actually motivated by a perverse desire to symmetrically fill out tables of 12 categories), and a pretty clear and intuitive way to separate the baby from the bathwater. So S boiled down Kant’s baroque a priori subjective framework to basically spacetime and causality. I think this might be a great insight that survives the invention of non-Euclidian geometry and relativity theory. Why? Because, for example, it does seem that our perceptual intuitions really are in Euclidian space, and when we envision curved spaces we do so in Euclidian space, such as a 2D spherical surface in 3D.

That said, it is still hard to go along with S (or Kant) when he concludes that there is no space or time for the thing-in-itself. That is, it is relatively easy to accept that each of our subjective worlds are subjective brain constructs, but to take the next step to say that real objects are not objects at all, and don’t exist in an external spacetime, even though we can independently experience them and “cross-check” their existence, is difficult. [cf. Zen koan #43 Shuzan’s staff: “Shuzan held up his staff before the assembled monks, saying “If you say this is a staff, you oppose its reality. If you say this is not a staff, you negate the fact. I ask you, what is this?”] Maybe the relational interpretation of quantum mechanics gives us a framework for realizing S’s version of “empirical realism, transcendental idealism.”

Before reading S, I thought that maybe his pessimism was overstated by religiously-minded critics as a lazy way of dismissing his theory. Now I have to admit that his pessimism is pretty deep. It’s almost funny at times—at one point he even remarks how depressing the discussion is getting. If he gives up the purposelessness of the will, though, he will lose a major advantage over every optimistic philosophy—namely, that the problem of evil and suffering is not really a (philosophical) problem for him. (It remains a personal problem.) There is no good or even intelligent God to be paradoxically responsible for evil and suffering.

On the other hand, he is arguably no more pessimistic than Buddhism, since he affirms a path to a form of salvation. Also, the will in his theory seems to harbor a hidden dynamic—or will—towards realization, where realization means individuation and objectification but also enlightenment. Thus, although he argues against the notion of any permanent progress, his own contribution to the real progress of philosophy might be seen as part of a universal evolution towards “universal enlightenment” or “heaven on earth.” It’s a bit of a stretch…

Bottom line: In terms of his utility for us as students of the mind-body problem, I don’t think we get any new ideas about how the line between conscious and unconscious brain processes would show up in biology. What we may get is a (provisionally) consistent metaphysics that relates mind and matter without elimination, and explains the real basis of our moral sentiments. It’s also a pre-Freudian explicit theory of the unconscious. If you’re into this kind of thing, it’s an exhilarating ride!

Friday, November 30, 2007

Below is the second part of Mike Wiest's review of The World as Will and Representation, Volume One. The first part is here. The next post will have his concluding thoughts. - Steve

Book 3—The Representation independent of the principle of sufficient reason: the Platonic Idea: the object of art:

On page 169 Book 3 (of Volume 1) starts:

“In the first book the world was shown to be mere representation, object for a subject. In the second book, we considered it from its other side, and found that this is will, which proved to be simply what this world is besides being representation. In accordance with this knowledge, we called the world as representation, both as a whole and in its parts, the objectivity of the will, which accordingly means the world become object, i.e., representation. Now we recall further that such objectification of the will had many but definite grades, at which, with gradually increasing distinctness and completeness, the inner nature of the will appeared in the representation, in other words, presented itself as object. In these grades we recognized the Platonic Ideas once more… In all these forms we recognize only the different aspects of the principle of sufficient reason that is the ultimate principle of all finiteness, of all individuation, and the universal form of the representation as it comes to the knowledge of the individual as such. On the other hand, the Idea does not enter into that principle; hence neither plurality nor change belongs to it. While the individuals in which it expresses itself are innumerable and are incessantly coming into existence and passing away, it remains unchanged as one and the same, and the principle of sufficient reason has no meaning for it. But now, as this principle is the form under which all knowledge of the subject comes, in so far as the subject knows as an individual, the Ideas will also lie quite outside the sphere of its knowledge as such. Therefore, if the Ideas are to become object of knowledge, this can happen only by abolishing individuality in the knowing subject. The more definite and detailed explanation of this is what will now first concern us.”

The distinct grades of objectification of the will are Plato’s Ideas, the “timeless prototypes of natural things.” Because all things are phenomena of one will, they are in some degree of relationship and harmony with one another; however, because the will is blind, the Ideas are in tension with one another, vying to manifest in phenomena. The complex balance of harmony and conflict produce phenomena in spacetime, causally ordered.

[S mentions that Platonism gets ridiculed, and it seems to be fairly unfashionable nowadays too, so I thought it might be helpful to mention a modern version of Platonism I came across recently in a paper by John D. Barrow called “Godel and Physics.” Platonism is not the subject of the paper, and is really just a manner of speaking rather than a developed theory. Still, this example made S’s Platonism a lot more digestible to my modern mind. In it, the Platonic Ideas are the symmetry groups that define modern elementary particle physics, and the different particle fields are different “representations” of the Lorentz group. “Representations” here is the actual technical math or physics term for the different “realizations” or “instantiations” of a particular symmetry group structure, so the physics meaning seems somewhat consonant with S’s usage.]

Now, there is a will-less state that reveals the Ideas in direct perception (as opposed to conceptually): the perception of the Ideas is the source of true art. Ideas are “generative,” as opposed to concepts which are abstracted from perception and “exhausted by their definition.”

S gives an interesting theory of aesthetics, the beautiful, the sublime, and art; in which music holds a special place as the direct analogue of the harmony of the different levels of objectification of the will. He develops an analogy between the hierarchy of tones in music with their foundation in the low, slow bass; and the hierarchy of levels of reality. [Here the discussion reminds me of a number of other vibration models of reality and perception, from superstring theory to the Greek Logos to kotodama, the science of spirit-sounds in Japanese Shinto.]

Book 4—The World as Will, Second Aspect: With the attainment of self-knowledge, affirmation and denial of the will-to-live:

Here S treats the ethical aspect of human behavior, the nature and extent of human freedom, and his notion of salvation:

Volume 1, page 272: “The point of view given and the method of treatment announced suggest that in this ethical book no precepts, no doctrine of duty are to be expected; still less will there be set forth a universal moral principle… Generally we shall not speak of “ought” at all, for we speak in this way to children and to peoples still in their infancy, but not to those who have appropriated to themselves all the culture of a mature age. It is indeed a palpable contradiction to call the will free and yet to prescribe for it laws by which it is to will. “Ought to will!” wooden-iron! But in the light of our whole view, the will is not only free, but even almighty; from it comes not only its action, but also its world; and as the will is, so does its action appear, so does its world appear; both are its self-knowledge and nothing more. The will determines itself, and therewith its action and this world also;”

So, from an absolute point of view outside of time, the will is free, but the will of any individual in time is determined by causes in time. There is an exception though:

Volume 1, page 287: “Man, however, is the most complete phenomenon of the will, and as was shown in the second book, in order to exist, this phenomenon had to be illuminated by so high a degree of knowledge that even a perfectly adequate repetition of the inner nature of the world under the form of the representation became possible in it… At the end of our whole discussion it will also be seen that, through the same knowledge, an elimination and self-denial of the will in its most perfect phenomenon is possible, by the will’s relating such knowledge to itself… In just this way, it exhibits the phenomena of holiness and self-denial… In this sense not only the will itself, but even man can certainly be called free, and can thus be distinguished from all other beings.”

From the point of view of causality, a person’s character is his fixed individual nature that determines the moral quality of his actions. In that context all our actions are fully determined by the intersection of our character with various circumstances (including the changing circumstance of our own growing knowledge about our own individual character as revealed by our actions). The above-mentioned freedom seems to manifest itself as a suppression of a human’s character, rather than an actual change of character, so that a sort of universal self-less personality emerges (p.403).

Page 404: “Now since, as we have seen, that self-suppression of the will comes from knowledge, but all knowledge and insight as such are independent of free choice, that denial of willing, that…only direct expression of the freedom of the will…is not to be forcibly arrived at by intention or design, but comes from the innermost relation of knowing and willing in man; hence it comes suddenly, as if flying in from without.”

[He approvingly quotes Christian descriptions of this phenomenon as the “catholic, transcendental change,” a “new birth” resulting from “grace” rather than natural causality. On page 405 he summarizes the extent of his agreement with Christian theology: “The doctrine of original sin (affirmation of the will) and of salvation (denial of the will) is really the great truth which constitutes the kernel of Christianity, while the rest is in the main only clothing and covering, or something accessory.”]

I’m generally pretty skeptical of “compatibalist” views of the relation between determinism and free will, but in S’s theory it does seem conceivable that the will that is the impetus for everything that is, when it realizes—i.e. creates—what it has willed, might wish to suppress itself, or at least its individualistic ego-centered physical-biological aspects. (Especially since it realizes all existence is “suffering,” fear and never-satisfied cravings, the dukkha of the First Noble Truth of Buddhism.) The will as thing-in-itself wills whatever it wants, freely, so when it realizes what it is—in a human brain, it may “change its mind.” The physical body may behave differently than it otherwise would have, but we might say the physical laws (for S these include causes, stimuli, and motives—all deterministic) are not changed or violated….It’s just that certain factors or forces have been reduced in amplitude, are not as strenuously fought for, but this change has no motive. Ultimately I can’t call this a deterministic theory, but it provides a scheme in which human behavior can transcend physical laws without directly violating them.

Here I’ve emphasized S’s treatment of freedom and determinism, but he also develops an interesting ethical theory. I find it to be a pretty intuitive model for moral realism. Though S says his philosophy won’t tell us how to behave, he explains that our actions nevertheless carry a real moral significance. Here is how he introduces the concept of “wrong”:

P334 “Now since the will manifests that self-affirmation of one’s own body in innumerable individuals besides one another, in one individual, by virtue of the egoism peculiar to all, it very easily goes beyond this affirmation to the denial of the same will appearing in another individual. The will of the first breaks through the boundary of another’s affirmation of will, since the individual either destroys or injures this other body itself, or compels the powers of that other body to serve his will, instead of serving the will that appears in that other body… This breaking through the boundary of another’s affirmation of will has at all times been distinctly recognized, and its concept has been denoted by the word wrong (Unrecht). For both parties instantly recognize the fact, not indeed as we do here in distinct abstraction, but as feeling.”

The feelings S is referring to are a “mental pain” of injustice in the victim and the “feeling of wrong committed” in the perpetrator. He develops this principle in a variety of cases, and distinguishes this negative ethical principle from the positive virtues that flow from the will-less consciousness. He discusses various approaches to the will-less state, and explains the distinction between the denial of the will arrived at by a clear objective perception from the apparent denial of the “will-to-live” in suicide. I won’t dwell on his ethical theory because I don’t feel competent to compare it to other approaches and attempt an overall assessment. But again, it seems to offer an intuitive metaphysics for a kind of moral realism—but with a more qualified freedom than one might expect from a moral realist theory.

(S’s final chapter of Volume 1 is an appendix on Kant, sketching K’s principal merits—which S earnestly considers to be epoch-making, as well as detailing his errors. I think Volume 2 is essentially further elaboration of the theory presented in Volume 1, and responses to objections composed over 30 years between the publication of Vols. 1 and 2.)

Schopenhauer claims at the outset that his entire book was aimed at and necessary to communicating a single thought. He states further that because of the organic inter-relationship among the aspects of that single thought, his book must be read twice to be fully comprehended (as, he says, with a great musical composition). I only read it once, but I think the thought is something like this: We can know Kant’s unknowable thing-in-itself, the true nature of the world, by direct conscious perception; and what this experience discloses is that all of our individual wills and consciousnesses are “phenomena” of a single, unconscious, universal will outside of time.Book 1—Representation:

The beginning of philosophy for S is to realize that this world of objects is our representation, and furthermore that all objects are for a subject: all objects are subject-objects. He thinks that only Kant’s teaching can effectively produce the insight that removes the “child-like realism in which we are all born.” And thus “My philosophy starts from Kant’s, and therefore presupposes a thorough knowledge of it.” In particular, Kant taught us the distinction between our experience of an object, the phenomenon, and its true inner nature or reality, the thing-in-itself. (Despite this statement I think one could read and enjoy S without having read Kant: S’s Kant is easier to understand than Kant in his own words.)

But Kant missed that the a priori framework for all experience (including time, space, and matter understood as the principle of causality) are all manifestations of one principle of sufficient reason, which says every event has a cause and implies universal determinism (—but this is not S’s last word on freedom!). This causal law and determinism apply to all objective phenomena, meaning that every event in spacetime has a cause in spacetime, which is the reason the event happened then and there. But because causes and effects in spacetime constitute the form of our subjective understanding of objects (they are prerequisites for being an object), objective phenomena are all for-a-subject. It may not be so difficult for a panpsychist to accept that all matter has a subjective aspect; the hard part is accepting that we cannot think of the thing-in-itself as matter (event protoconscious matter) evolving in spacetime. Again, the matter model is perfectly effective empirically, for describing the network of objects and causes, but we have no inkling of the thing-in-itself behind our representations (this will change later in the book). Thus, our causal reasoning cannot be used to explain the origin or form of the fundamental forces, nor anything outside the causal network. Similarly, there can be no question of a causal relationship between subject and object, in either direction. Rather, subject and object are necessary poles of all objective existence in spacetime.

Now, S thinks that Kant and many other philosophers have been confused about perception and its relation to concepts and rational thought. For S perception is already intellectual (or cognitive). In particular, perception is immediate causal understanding (an intuition based on normal context, called illusion when wrong). For example, rather than merely sensing a two dimensional pattern of colors, I perceive “(this sensation in my visual field is caused by) an object nearby in 3D space in front of me.” This faculty we have in common with animals. Reason is a basically uniquely human faculty that uses concepts abstracted from perception to reach conclusions about past and future events (called error when wrong). This ability liberates us from the present. S has a nice pictorial way of representing reasoning (using Venn diagrams) as a procedure of passing between different concepts by means of what they have in common. He claims this simple framework can account for all our reasoning. Kant’s error in this context is roughly that he takes concepts to be primary and perceptions are to be understood in terms of concepts, whereas S teaches that all original evidence lies in perception, and concepts merely systematize, fix, and communicate evidence from perception.

[I’m not sure yet how I feel about the relational interpretation of quantum mechanics. But from this line in the Stanford Encyclopedia article about it, it seems to be a specific instantiation of S’s doctrine that objects and their various properties exist only relative to a particular observer: “Quantum mechanical relationalism is the observation that there are no absolute properties: properties of a system S are relative to another system O with which S is interacting.”]

Book 2—Will:

It’s what Kant missed when he said the thing-in-itself is absolutely unknowable. Considering things objectively, from the outside, we can never fathom their inner nature. But S points out that there is one thing whose inner nature we have special access to. S says that in reflecting on the contents of our own consciousness we find something absolutely distinct from all the objects in our representation (i.e. even subject-objects), namely feelings that reflect our will.

Volume 2 page 202: “…Not only willing and deciding in the narrowest sense, but also all striving, wishing, shunning, hoping, fearing, loving, hating, in short all that directly constitutes our own weal and woe, desire and disinclination, is obviously only affection of the will, is a stirring, a modification, of willing and not-willing, is just that which, when it operates outwards, exhibits itself as an act of will proper.”

Our will is often unconscious, but in experience it manifests pleasurable and painful states where our preferences are apparent, like anger and lust. Of course the various passions are usually experienced as entangled with our representations of our body and other bodies in spacetime, but for S the road to truth is to clarify the distinction between them. The point is to realize that our will is our deepest reality, our innermost essence (not our intellect, which serves the will, and is in fact “objectified” will). The next—big—step is to see that my inner nature, my true existence, is identical with the thing-in-itself of the whole world.

So we are to understand that the apple’s falling and the seedling’s sprouting are impelled by the same will (though unconscious) that ultimately drives us. This world is the objectification, or mirror, of will. We cannot consider it as multiple because space is the principle of individuation, which exists only in our representation. It is outside of all causation, but the world of causes in beginningless time arises out of it. Grades or levels of objectification of will correspond to inexplicable laws or entities that must be presupposed in our causal explanations. For example, physical causes, stimuli, and motives all necessarily bring about particular effects in particular circumstance, but represent different levels of objectification of will. Physical causes lead to an effect that is of the same physical magnitude as the cause, whereas stimuli are small causes that lead to large effects, and motives are causes that have passed through knowledge, i.e. through a conscious brain process. [To me this is account of the objective world as a shell whose inner being is mental in nature is reminiscent of Gregg Rosenberg’s contemporary account, in which causality is carried by experiences corresponding to a hierarchy of natural individuals, and the temporally ordered flow of events arises from some kind of meta-temporal nexus of events.]

The thing in itself, the universal will outside of time, is unconscious and purposeless, a blind “procreant urge of the world” (that’s Whitman, not S). But we can also say that it wills to live:

Volume 1, page 274: ‘The will, considered purely in itself, is devoid of knowledge, and is only a blind, irresistible urge, as we see it appear in inorganic and vegetable nature and in their laws, and also in the vegetative part of our own life. Through the addition of the world as representation, developed for its service, the will obtains knowledge of its own willing and what it wills, namely that this is nothing but this world, life, precisely as it exists. We have therefore called the phenomenal world the mirror, the objectivity, of the will; and as what the will wills is always life, just because this is nothing but the presentation of that willing for the representation, it is immaterial and a mere pleonasm if, instead of simply saying “the will,” we say “the will-to-live.” ‘

We are the highest level of reflection (i.e. objectification) of the will.

Saturday, November 17, 2007

Discussed in a short essay by writer Jim Holt. Overall, a nice advertisement for the idea, with mentions of Nagel, Chalmers, and Galen Strawson. If only he could have resisted the urge to use the "thinking rock" trope!

Tuesday, November 13, 2007

In recent years, a new school of quantum gravity research has come into view. The research programs in this group attempt to demonstrate that neither the matter fields nor the space-time geometry described by our present theories are fundamental, but instead both co-emerge from a pre-geometric quantum mechanical foundation. (Links to my prior posts on this research are at the end of this post). Olaf Dreyer is a theoretician working in this mode. He recently presented this paper, “Why Things Fall”, which nicely summarized his work to-date (hat tip: this thread maintained by marcus at Physics Forums).

What helps make the paper accessible is that Dreyer’s approach has been to work at a very stylized conceptual level. He wants to show how the path to a full theory should go, with the goal of filling in crucial details later. It is clear that this kind of theory has a long way to go, in particular to show that Einstein’s equations will specifically emerge.

In the introduction, Dreyer describes the approach where gravity is not assumed at the outset but is emergent. He breaks this down further by discussing the constraint that there is to be is no clean distinction between the emergent gravity and matter degrees of freedom (as opposed to an approach like early string theory where the graviton emerged as part of the particle family). Rather, it is only through the matter degrees of freedom that we infer the geometry. He says: “…we are taking seriously the fact that we only know geometry through matter…geometry alone is not accessible to us. (p.2)” This description of the emergence of geometry is in contrast to an approach like loop quantum gravity, where the space-time geometry of general relativity is taken as given and then quantized. What makes the theory a quantum theory of gravity is that the matter degrees of freedom and inferred geometry will emerge from a foundation which is quantum mechanical. One consequence of adopting a QM system as fundamental is that background time is assumed at this foundational level, although it will have no relationship to emergent space-time. I have no problem with this: something has to be fundamental and I think time and asymmetric causality are good candidates for this role.

The term “internal relativity” is meant to stress a key point: we ask what geometry obtains from observed degrees of freedom from a point of view within the system. Dreyer believes that if we do this, relativity naturally will emerge.

As a prepatory example, Dreyer shows (in section 3) how something like this happens in a classical theory. Specifically, if we start with an electro-magnetic field (on a Newtonian background of absolute space and time), we can see how special relativity emerges from considering how the dynamics of charged particles gives rise to contraction/dilation effects from a point of view inside the system.

Section 4 presents the main model of the paper. Dreyer begins with a simple quantum mechanical system in a ground state (level 0). Then he allows for excitations (traveling spin waves in the model). This is level 1, and the excitations are meant to be analogues of elementary particles of our world. Level 2 is given by bound states of these excitations. These bound states are meant to be analogues of the solid objects of our world. They do not leave the parameter on ground state of level 0 unchanged. Dreyer analyzes the effect of the objects on the distribution of the level 0 parameter and is able to derive Newton’s law of gravitation between the objects in a low velocity approximation. He then says the presence of Newtonian gravity means that the geometry seen by internal observers will be not flat but curved (a curved Lorentzian manifold). So while Newtonian gravity was derived, the overall framework implies something which goes beyond Newtonian gravity. He notes that the model falls short of showing that the gravitational mass implied for the bound objects is actually the same as the inertial mass.

Section 5 concludes with some discussion. Dreyer reiterates the concepts involved in having matter degrees of freedom and gravitation emerge from a fundamental level that has distinct degrees of freedom. He discusses how certain problems don’t arise in this conceptual framework, such as the “problem of time” which arises when one quantizes space-time, and the problem of incorrect predictions for the value of the cosmological constant. He also discusses some very preliminary ideas for observable consequences which may follow from this kind of theory.

Monday, October 29, 2007

I didn’t mention this in my post on panentheism, but prominent among theologians who endorse a form of panentheism are the process theists, such as John Cobb and David Ray Griffin (co-directors of the Center for Process Studies) and their influential predecessor, the late Charles Hartshorne. These theologians take as a starting point the work of Alfred North Whitehead, specifically the speculative metaphysics presented in his late work: Process and Reality, written in 1927-28. Whitehead himself was not a theologian -- originally a mathematician, he was for years a leading logician and philosopher of science. However, at the end of his career, when it came to fashioning his grand system of process philosophy, he did assign a role to God in his scheme. The result, as A.D. Irvine explains in his SEP article on Whitehead, was a skewed legacy: “Thus although not especially influential among contemporary Anglo-American secular philosophers, (Whitehead’s) metaphysical ideas have had significant influence among many theologians and philosophers of religion.”

I find the way things fell out here interesting. On the one hand, Whitehead’s work was eagerly received by religious thinkers who wished to fashion a theology which improved on classical theism. On the other hand, secular philosophers mostly ignored his work, a response not especially surprising given the prevailing 20th century attitudes toward metaphysics in general. But neither group’s perspective seems to do justice to Whitehead’s own situation: a non-theologian who found that following through on the development of an innovative philosophy led to the inclusion of God in the system.The late Victor Lowe, who wrote a biography on Whitehead, wrote here about what he learned about Whitehead’s attitude toward God and religion. According to Lowe, Whitehead (1861-1947) started his life as a believer, but became an outspoken agnostic, and remained so through much of his philosophical career. Lowe cites the reports of family members, however, that later he may have begun to turn back toward theism, possibly in reaction to the tragic events of World War I, including the death of his younger son. Lowe also cites evidence, though, of an ongoing ambivalence toward God throughout the rest of his life. In any case, however, given the paucity of evidence about Whitehead’s thinking outside his published work (he left no pertinent letters, diaries, etc.), the hard evidence for a turn toward theism must be derived from his late metaphysical writings. As discussed below, the “theism” found there comes in a purely philosophical context, not from any appeals to experience or authority. And it remained pretty clear from this work that Whitehead, as Donald Viney puts it here, “had little truck with organized religion.(p.7)” (please note Viney also wrote the comprehensive SEP entry on Process Theism.)

Looking at Whitehead’s own words in P&R (Part V, Ch. II, Section I), he dismisses the traditional concepts of God as imperial ruler, personification of morality, or unmoved mover. He says “Hume’s Dialogues criticize unanswerably these modes of explaining the system of the world (p.343).” Whitehead wants to dispassionately analyze what his metaphysics requires God’s nature to be. He also says: “There is nothing here in the nature of proof.” His says his efforts can be thought as “an attempt to add another speaker” to the Dialogues (p.343).

The scheme in P&R (to be brutally brief and imprecise) involves re-describing the world in terms of a new elementary constituent -- an extended event or process -- called an actual occasion. Each actual occasion begins with a subjective perception (a “prehension”) of prior or adjacent events, and then proceeds to a completion of the process via a creative or spontaneous choice among available possibilities. The completed occasion then becomes the objective input for new occasions. The ontology of actual occasions offered a novel way for making sense of how mind fits into a thoroughly experiential world and how a theory of “real” causation might work. God serves three roles in the system. First, God is the principle of creativity which participates in all events. Second, his “primordial nature” provides a ground for eternal objects – the abstract entities which serve as examples or goals for events. Finally, his “consequent nature” is as a home in which completed events reside. Later in the chapter quoted from above, Whitehead discusses these attributes and makes some comparisons of this description with other conceptions of God.

Now I’m no expert, and it has been a few years since I struggled through all of P&R. But it seems that for the actual occasions of the world to do their job, they need the presence and the participation of God. God is the entity in the system which provides the creative impulse, the template for choices, and the ground for completed events.

Others disagree: Donald W. Sherburne, the Whitehead scholar who wrote a helpful companion volume to P&R, argued against the need for the roles played by God and he worked on a project to “naturalize” Whitehead. This is something I want to look at further. But even if the roles played by God are required, the decision to name the system’s transcendent entity “God” appears to me to be a choice rather than a requirement, given how distinct this entity is from the God of tradition.

I have a high regard for Whitehead’s process philosophy; it seems every time I look at his work (although it is very difficult reading) I find that many of the philosophical ideas discussed on this blog are present or suggested there. Perhaps then, I should just respect his decision to include God in his work and not try to quibble with this. But my main point in discussing the issue is to stress my view that secular “analytic” philosophy has a lot to learn from Whitehead’s metaphysics. And I would hope more can engage with his philosophy without letting God “get in the way”.

Several of the authors in the volume offer definitions of panentheism; the one from the Oxford Dictionary of the Christian Church seems a good starting point: “The belief that the Being of God includes and penetrates the whole universe, so that every part of it exists in Him, but (as against Pantheism) that His Being is more than, and is not exhausted by, the universe.” (BTW, my post on plain old pantheism is here).While there are strands of panentheistic thought which extend throughout history, Peacocke’s introductory essay sets out many of the reasons a contemporary theist might move toward panentheism from a starting point of classical theism. He says a variety of factors form the basis of this impetus: “Broadly they all point to the need to accentuate, in light of contemporary knowledge of the world and of humanity, a much stronger sense than in the past of the immanence of God as in some sense “in” the world (p.xix)”.

Importantly, it is the influence of the scientific account of the world as a seamless web of natural phenomena which “…has rendered it increasingly problematic to conceive of God’s action in the world as intervening in any way that involves an abrogation of the very regularities with which God’s own self is regarded, by theists, as having endowed the world (p.xx)”. Further, Peacocke points out that the scientific explication of how natural systems evolve and emerge through self-organization leads toward a reading of God’s work in the world as “…creator ‘in, with, and under’ the creative, natural processes of the world unveiled by the sciences (p.xx)”.

Another important driver is the increased implausibility of a strong mind/body dualism, given advances in cognitive science and neuroscience. This “…has inevitably reflected upon the use of traditional models of God’s relation to the world in terms of personal agency. In these models God’s actions on the world was analogous to a person’s intentions being implemented by bodily actions…much traditional theology has implicitly been based on dualistic models (p.xxi).” Again, a view of God’s action being continuously present through natural processes seems more plausible.

Still, as against pantheism, a panentheistic model also preserves the transcendence of God, preserving a distinction between God and world. Thus for most of the contributors to this volume, coming from a theistic background, panentheism offers the possibility of a middle ground.

But, what if you are approaching things from a non-theistic perspective? If our world is a subset of a larger metaphysical entity, what’s the motivation for taking a theistic perspective on this entity at all, apart from the aspect of transcendence?

Well, there are a couple of other aspects of the philosophical model I’ve been working on that might support this perspective. First, reality is inherently experiential. Our world is comprised of events which are physical when viewed from the third-person perspective, but experiential from the first-person view. Possible events which are unactualized from our local point of view are experienced from a distant point of view: the full manifold of events, we might imagine, is being experienced across the full sum of points of view. Further, I have argued that our causal contact with the larger space of possibilities may provide the grounding for our rational faculties, including our knowledge of abstract objects. Rationality is based on knowledge of logical possibilities, which is founded on our contact with real metaphysical possibilities. According to the thesis of modal rationalism, metaphysical and logical possibilities are the same. Thus, rationality maps the terrain of modal space, or alternatively, is a reflection of the “shape” of God.

On the other hand, in this conception, it still seems problematic to me that the manifold of possibilities is a “person”, even if it encompasses experience and grounds reason. In the absence of personhood, is it still God? Also, while I can summon up feelings of awe and wonder with regard to this entity, I can’t see why one would worship it. I suppose it is possible that whether or not you take a theistic or religious stance toward this entity might be a question of personal preference or psychological makeup, but I’m not sure (I ran up against this issue in an old two-part post called “The God Option”).

In any case, it’s interesting that the course of philosophical reasoning can at least move one into this terrain. It gives me some hope that a worldview which has independent motivation could also serve as a potential meeting ground for those looking to improve on both classical theism and classical materialism.

Wednesday, September 26, 2007

I feel I’ve been inconsistent. On the one hand, wearing a philosophy hat, I’ve endorsed a form of modal realism, where our actual world is a subset of a full expanse of metaphysical possibilities. On the other hand, when I wrote about multiverse models offered by theoretical physicists, I downplayed the "actual" reality of the distant regions described in such theories.

I’m thus returning to the old question of what, if any, is the relationship between the philosopher’s space of possible worlds, and the multiverse described by some physical theories. What should one’s stance be toward each of these? I think I have a clearer thought on this; but first let me digress briefly to say what led me to it.
For awhile I’ve wanted to identify the “actual” world with the region we have causal contact with. The reason for this is motivated by my preferred model of causation and ontology, which says that the familiar concrete world consists of events which are actualized possibilities. In an earlier post I stated this and thus proposed that physical models which contained models of the universe or multiverse beyond this region were describing things which were not actual, but only possible. The clear implication to the reader is that the regions so described were “less real” than our neighborhood. Clark, his comments, questioned whether I could justify discounting all the various multiverse theories. Alejandro described my stance as anti-Copernican: the idea being that our particular neighborhood shouldn’t be viewed as special in this way, given a sound theory which describes our region as well as points beyond. I think this was good criticism.

Now, however, in the context of modal realism, I have this idea that it is consistent with my ideas that “actual” be considered an indexical term (see prior post). In this case I can still denote our causal region as actual, to fit my idea of causation as the process of actualizing possibilities or propensities. However, there is no intent to say our region is special. The terms actual and possible are relative to a local point of view. There is nothing special about our region – from the point of view of an observer elsewhere, the concrete events familiar to us are unactualized. And I think this stance can be appropriate in the context of physical multiverse models as well as in the metaphysical context where it arose. The actual world has a different status then the regions beyond our contact, but this is a relational distinction, not an absolute one, and thus not in itself a rejection of these attempts to model distant reality.

So, given that conclusion, what can be said about the relationship between the metaphysical and physical multiverses? The philosophically motivated idea is that of a space where every metaphysical possibility exists. This is equivalent to saying every logical possibility exists if we endorse modal rationalism. Our actual world is one island in this expanse. I see multiverse theories offered by physicists as attempts to model particular subsets of this space by allowing for the extension or variation of our physical events and laws (as best we know them so far). Such theories widen the realm of nomological possibility – and as you widen this scope more and more you begin to converge toward the ultimate space of metaphysical/logical possibility.

Monday, September 17, 2007

David Lewis’ theory of modal realism features a collection of concrete worlds, which are spatio-temporally connected societies in themselves but wholly isolated from one other. We live in one of these, which we call the actual world; the others we call possible worlds. But there is nothing special about being “actual”; it just refers to where we reside: actual is an indexical term.

In sketching my own ideas, I’ve rejected Lewis’ theory, but I’m now considering that his sense of actual may be the right one for my model as well. What follows is some “work-in-progress” thinking on this. (My modal realism posts are here).

Lewis’ worlds are completely separate, and they are static entities; his treatment of causation is Humean in spirit. On the other hand, in my preferred view, causation is a process of actualizing possibilities. The actual (concrete) world consists of the events we are already in causal contact with. At any given moment we are surrounded by adjacent (abstract) possible events which are available for our actualizing. More distant possibilities (and possible “worlds”) are rational constructions based on our experience with possibility (they are also accurate in their representations, if we embrace modal rationalism).

To those modal realists who disagreed with his account, and preferred to think of possible worlds as abstract objects, Lewis demanded an account of what magic accounted for the instantiation of one of the worlds as actual. But in my idea, it is not an entire world that is instantiated as actual all at once, rather a series of events are actualized through an active causal process. So it wasn’t clear that Lewis’ objections would apply in the same way.

We are on a journey through a space of possible events, actualizing certain ones as we go. At first, I thought this meant we are something magic or special in that we are blazing a causal path of actualization against a backdrop of a space of unactualized possibilities, and so I was feeling the bite of Lewis’s critique of his opponents: how can I account for our actualized “world” being thus special vs. the rest of the possibilia?

Then I realized that the mistake was to picture the space of possibilities as static. This was a hangover from Lewis’ model. In my model, a “possible” event is one we have not been in causal contact with from our particular perspective. But, from a different point of view this event could be actualized. Possibilities and actualities exist relative to a particular perspective. We just label the events unfolding in our local causal nexus “actual”, and the rest “possible”. All the events of modal space can be thought of as in an active process of becoming actual. The multiverse is alive, not static. And we are not special, after all.

Monday, August 20, 2007

I was thinking about the role intuitions play in philosophy and I found a nice paper by Steven D. Hales called “The Problem of Intuition”, which was published a few years ago. It contains a discussion of the role of intuition in philosophy and then presents an argument that philosophy is unavoidably founded on rational intuitions which have no external justification. This need not be viewed as a bad thing if we accept that some propositions can be self-justifying: they are the intuitive axioms upon which further reasoning is grounded. I thought Hales’ analysis in the paper made sense.

It’s worrisome, of course, that many of us seem to bring conflicting intuitions to philosophical debates. Yet I think we can still hope that we can find a secure shared foundation of at least some intuitive axioms.

So, what are they? What are yours? Famous philosophers of the past tried hard to base grand philosophical systems on carefully considered intuitive first principles. That style of philosophy is rare today. The long history of scientific advances overturning common sense intuition about empirical facts has inspired some philosophers to extrapolate further and argue that many of the deep intuitions we all presuppose in our daily lives are actually wrong and the result of illusion.

Two bedrock intuitions I view as axiomatic have been called into question by philosophers of a naturalistic bent. I maintain that there is no scientific finding or valid inference from the sciences that contravene these.

In considering these two I’m not saying that our common sense intuition about the nature of the conscious self and free will is accurate. Cognitive science and neuroscience will continue to reveal deep flaws in our “folk” conceptions of self and will. This is to be expected given that we are complicated composite organisms. But it is a mistake to infer from this that the axioms above are false.

Thursday, August 02, 2007

While in previous posts I quibbled with some of the ontological details of Molnar’s theory, I think there are bigger problems which ultimately undermine his approach. These problems center on modal issues. On the one hand, the positing of necessary connections between powers and manifestations to explain causality is too easily rejected by the adherents to a Humean view. On the other hand, from the perspective of a reader sympathetic to causal realism, the theory has the wrong modal structure to support an asymmetric causality which matches our intuition. At the end of the post, I argue that the recasting of powers as propensities can lead to a superior theory.

The theory of powers is motivated by a desire for causal realism. The alternative Humean view is that causality has no mind-independent reality: the world has regularities, but not causation. Now, the nature of a power is only revealed by its manifestation. For this reason, Molnar explains that it is a feature of the theory that the connection between a power and its manifestation is a necessary one. Hume, at least in the usual modern interpretation, denied the existence of necessary connections between distinct things (recall a power is distinct from its manifestation, since it can exist in the absence of the manifestation). While Molnar argues that Hume’s dictum can be rejected, as it ultimately leads to an overly corrosive skepticism, many philosophers would apply the dictum in this case. It’s especially easy to see this for those who would take a four-dimensional block perspective on the universe as a model. How would the events in the block universe alter if we removed these necessary causal connections? The answer is not at all. So, the ontologically sparser view is deemed superior.

But of course, the block universe model implies there is no mind-independent asymmetric causal flow in nature. If the theory of powers can help us explain the kind of “real” causation which matches our intuitions, shouldn’t we endorse it?

Well, by my reading, Molnar’s theory of powers doesn’t achieve this goal. The asymmetry of causality means the past is fixed while the future is open (please note I’m not committing to a global evolution in conflict with relativity). Molnar doesn’t have the right modal structure for this asymmetry. For a given causal past (which is determined), we need to explain what happens next (which is undetermined). To recap the theory, there are necessary connections between powers and manifestations; also, recall that powers actually exist, and do so even when not manifested. So how does this explain the fact that manifestations sometimes occur and sometimes don’t? How can a necessary connection give us a possible manifestation?

Molnar explains that the causal effects we normally think about are actually complex conjunctions of power properties and some non-power properties. This can explain the apparent existence of indeterminism in our perception. But at the mind-independent fundamental ontological level, there doesn’t seem to be any basis for indeterminism in the theory.

I think the solution would be to sacrifice the actuality of powers and turn them into propensities. I’m defining a propensity to be a power which is a possibility. A manifestation event is the actualization of such a possibility. Molnar considers this idea very briefly and rejects it in just a couple of paragraphs. He evidently takes it as a given that something which is “merely” possible cannot enter into causality.

The ontological cost of admitting causally relevant possibilia seems high to many. We need to replace the traditional ontological division between the “actual” and the “merely possible” with a modal realist vision which admits a role for possibilities which are “real” enough to enter into causal relations and be actualized. The specific combination of power/propensities and/or other kinds of properties needed to achieve an actualization event can be worked out in more than one way. Gregg Rosenberg’s theory is a recent one which features this kind of modal realism. In his model of causation, two types of properties (effective and receptive) are needed for actualization. Jennifer McKitrick recently reviewed Rosenberg’s book and offered detailed comments on his model of causation. While her criticisms were often perceptive and thought-provoking, she also had (in my opinion) a surprisingly hard time grappling with this sort of modal realism.

P.S.
For a critique of the theory of powers which approaches from a somewhat different angle (but also is skeptical about the modal nature ascribed to powers by Molnar as well as McKitrick), see the paper “What Do Powers Do When They Are Not Manifested?” by Stathis Psillos, available on his website. Thanks to Antonio for alerting me to this paper.

Friday, July 20, 2007

I’m very interested to learn of any discoveries regarding the utilization of non-trivial quantum effects in biological systems. (I wish I could follow developments more effectively then just the occasional internet search.)

Anyway, back in April a paper in Nature appeared discussing the meaningful role quantum coherence plays in photosynthesis. Here is the press release from the research team at the Berkeley Lab. Here is a short piece in Scientific American (Access to the Nature paper requires subscription -- a related paper in Science followed in June.)

This seems like a big deal to me – this is a central topic in biology – and until now biologists incorrectly assumed only classical mechanisms were being used.

If natural selection made use of quantum coherence in this case, it seems likely we should find it exploited elsewhere by living things.

Tuesday, July 17, 2007

Powers (or dispositional properties) are the centerpiece of George Molnar’s causal realist metaphysical model. The following question arises: are powers the only sort of property, or are there others?

Molnar considers whether powers (with the features he ascribes to them) could be the star players in an ontological monism (called pan-dispositionalism). It would seem that adopting pan-dispositionalism, along with the natural assumption that manifestations of dispositions constitute changes in the properties of objects, leads to a regress. Powers only manifest as changes to other powers. But is this a vicious regress? Molnar considers a couple of arguments that it is indeed vicious. If objects are things which take up space, then powers need to be joined by space occupying properties in order to constitute objects. But a look at particle physics seems to show that elementary constituents of nature do not have volume or occupy space in the way common sense implies. So this doesn’t seem to be a convincing objection – it’s not clear that objects need “space-occupying” non-power properties. A second objection says that objects need to have non-power properties which are qualities. But are there mind-independent physical qualities? What are they? Candidates such as size, shape, color are all phenomenological, rather than fundamentally physical, according to Molnar.

Molnar doesn’t see that the regress objections are fatal, but nevertheless concludes pan-dispositionalism is unlikely to be true for a posteriori reasons. Since powers are intrinsic to objects (in his theory), he considers the reality that they are “portable”. They are not necessarily altered if I move the object somewhere else. He sees the need for non-powers which are responsible for what scientists call symmetry operations (hence “S-properties”). These are essentially positional properties (positions in space-time) with one exception – if parts of a complex object have identical powers, and they exchange roles (say swapping the two hydrogen atoms in a water molecule), the powers of the complex object are not affected. This is a property of numerical identity.

So, Molnar does end up with a property dualism. There are powers, which are intrinsic dispositions of objects; and there are non-powers, which are extrinsic and basically have to do with placement of objects in space-time.

Comments:Certainly, as property dualisms go, this is a pretty bare bones version compared to what the term “dualism” usually connotes. On the other hand, while Molnar is presenting a pretty ambitious metaphysical system, he is not trying to explain the mind, which is what traditionally motivates dualistic theories.

One critique I have centers on Molnar’s reliance throughout on his interpretations of physics. Powers are deemed intrinsic because, for instance, charge seems like an irreducible property of an electron. He says qualitative properties like size and shape don’t exist, because they do not feature in physics. He argues positional properties make sense because of symmetry operations which can be conducted on physical systems. A mostly unstated but crucial assumption underlying all of this is a somewhat old-fashioned view that physics supports the conception of objects moving around in a static space-time container. So a theory of powers which is motivated largely by a priori analysis of causation has its details shaped by these a posteriori inputs from physics. There are a couple of obvious concerns: first that his interpretations of physical theories may be incorrect, and second, that the theories he’s interpreting are provisional and may be superseded.

We don’t have a final theory of physics yet, but we can make an educated guess that the conception of objects moving in a space-time container (already extremely distorted in quantum field theory) will not survive. In General Relativity, there is a dynamic interaction between space-time and matter fields, and this seems to compromise the separation of properties into powers and positional properties (doesn’t a dynamic space-time need powers, too?). Further, in some quantum gravity research programs (my favorite ones), both space-time and matter fields are seen as emerging from a more fundamental basis (specifically a causal network of quantum mechanical interactions).

Still, the idea that positional properties are needed seems right to me. The nature of quantum mechanical propensities appears to depend on the relation between quantum systems. In a theory featuring a causal network of quantum mechanical interactions, causation would depend both on propensities (powers) and position in the network. One thing I think we could drop altogether is the idea of an object. What we think of as objects would be complex patterns of causal events in this way of thinking.

Thursday, July 05, 2007

George Molnar sets out 5 key features of power properties: directedness, independence (they exist whether manifested or not), actuality, intrinsicality, and objectivity (mind-independence). His discussion of directedness is very interesting, as he argues that the directedness of powers has all the elements associated with intentionality. Therefore, the existence of (mind-independent) causal power properties means that physical intentionality is a ubiquitous feature of the world. (Please note the title of this post is my creation, and not a term used by Molnar).

The paradigm accounts of intentionality are those of mental intentionality due to Brentano and like-minded philosophers. In fact, Brentano took intentionality to be what distinguishes the mental from the physical. In philosophy of mind, a debate of the following sort has taken place: a dualist would make the case for the uniqueness and irreducibility of mental intentionality; a materialist would (rarely) claim that introspectively revealed intentional mental states are illusory, or would (more commonly) argue that physical things also exhibit intentionality and either take an instrumentalist rather than realist view of the whole phenomenon, or suggest a way to reduce it to non-intentional physical description. The dualist might counter that the examples of physical intentionality (a map, for instance) are all examples of derived intentionality with true mental intentionality being the origin of these seeming cases. (There is obviously immensely more to these debates than this caricature: see this SEP article).

Molnar turns this all around. He accepts the existence of mental intentionality and argues that “something very much like intentionality is a pervasive and ineliminable feature of the physical world.” (Emphasis original, Ch.3, p.61).

He presents these parallels between the directedness of powers and the intentionality of mental states:
1. Physical powers, like mental states, are directed towards something beyond themselves. In the case of the power, it is directed toward its manifestation.
2. In both cases, they can exist even if their intentional object does not exist. A power can remain unmanifested.
3. There can be indeterminacy about the intentional object. The power can be a propensity toward a manifestation.
4. Finally, Molnar describes a parallel between two semantic criteria for the intentional as applied to the two cases: the non-truth functionality of the intentional reference and referential opacity.

Molnar considers several possible objections to the notion of physical intentionality.

He looks at objections which try to point out other distinctive aspects of mental intentionality which counter the analogy. It seems there can be impossible intentional objects and absolutely unique intentional objects in the mental realm but not in the physical. He thinks there are merits to these cases of potential disanalogies, but in the first case, representations of impossible objects are a minor and atypical example of mental states, and in the second the uniqueness seems to depend on the experiential rather than the intentional nature of the state. These cases don’t make intentionality the demarcation between mental and the physical. So the analogy seems robust enough.

The most important possible objection has to do with the relationship between intentionality and meaning. Mental states are directed toward their intentional objects by representation, where the representation (whether pictorial, symbolic or in some other form) provides meaning. The states are “about” the objects. It seems we can’t extend this to the physical: power properties do not represent. Solubility is directed toward the dissolving of the solid, but doesn’t feature a representation of the event: it isn’t “about” it, in that way. Molnar’s strategy, here again, is not to deny the presence of semantic properties of mental states, but to loosen the tie between representation/aboutness and intentionality by pointing out paradigm cases of mental intentionality which do not include aboutness.

He points out that even in the case of perception, the perception cannot be wholly reduced to a representation. But he concedes it still has a great deal to do with representation. A much better example to use for a mental state without representation is in the realm of bodily sensation, and specifically pain. Pains are mental states which meet the four criteria for intentionality discussed above. But do pains have meaning above and beyond these intentional features? Are there representational features? Molnar says no: “…a headache does not represent my head hurting, it is my head hurting.” (Emphasis original, p. 77) The only sense it makes to say that the pain represents the bodily hurt involved is in a sense where you might say an effect represents its cause. And of course one could say this in cases of physical causation as well. If this is meaning, it is a form of natural, non-representational meaning. Molnar expands on the example to assert there are two kinds of mental intentionality, roughly corresponding to a traditional distinction between the rational and the sentient. The first can be analyzed in terms of representational content of the state, the second cannot. The second kind is the kind which is also true of the power properties of the physical world.

A last objection, of interest to me of course, is referred to by Molnar as “the threat of panpsychism” (p.70; why it is so darn “threatening”?). The argument is that the case for physical intentionality actually makes the case that the mental realm is co-extensive with what we think of as the physical realm. Molnar says he would not endorse this argument, because while he is ruling out using intentionality to demarcate the mental from the physical, there should be other ways of doing so, such as the “capacity for consciousness”. But, alas, this goes beyond the aims of the book. It is my view that the most elegant and compelling metaphysical account sees the human mind as a (particularly interesting) complex instance of a natural causal nexus which is ontologically grounded in the same way as the rest of the universe. No ontological demarcation is needed or wanted.

Tuesday, June 26, 2007

George Molnar’s Powers: A Study in Metaphysics appeared in 2003, with a paperback version following recently. The book presents a realist theory of causal metaphysics founded on a detailed ontological treatment of dispositional properties, or powers. Molnar’s work was brought to my attention last fall by an e-mail correspondent, to whom I’m grateful. I plan to present some notes and thoughts about the book over a couple of posts.

The book is a posthumous publication, Molnar having died in 1999. Some brief biographical information is provided in the introduction by Stephen Mumford (see also this webpage [UPDATE: 8 March 2011 - this was a link to a page about Molnar - now gone), as well as in a preface by D. M. Armstrong. Born in Budapest, Molnar and his family escaped the Nazis and he settled in Australia. He became a philosopher and published a handful of metaphysical papers early in his career. Then leftist political activities led him to depart his university post and exit formal academic philosophy for a couple of decades until just a few years before his death. In those years, this book took shape.

According to Mumford, who prepared the manuscript for publication, the chapters which present the main theory were largely complete; the manuscript lacked an introductory chapter and only fragments existed of the intended final chapters on application of the theory of powers to various metaphysical problems. Mumford has provided a helpful introduction, and edited the final fragments into a condensed last chapter.

Molnar’s theory is a realist account of dispositional properties as causal powers. This realism about dispositional properties and causality is in contrast to work in the Humean tradition which would eliminate dispositional properties and reduce apparent causal power to mere correlation. A traditional strategy is to employ a conditional analysis. Rather than ascribe the dispositional property of solubility to X, one simply notes that if X is placed in water, then it will dissolve. Another way to approach eliminating powers is to claim they can be reduced to categorical micro-physical properties (although many would view charge, mass, spin et. al as paradigm dispositional properties). Molnar will defend dispositional properties as real and ineliminable causal powers of objects.

Molnar’s Ontological Categories

A. Tropes. Molnar wants to present a full ontology of powers, so he must answer the question: what kind of properties are they? His answer is that properties are tropes. He thinks that nominalists are right to distrust the idea that properties as universals are real but err in rejecting all realism about properties. Realists are right in their realism, but wrong about universals, which are too inconsistent with naturalism. There are sections discussing the characteristics of tropes in great detail in Ch. 1, which I will pass over for now. I should note that in addition to powers, Molnar will find a need for non-power properties as well, leading to a property dualism.

B. Objects. There is a classic problem with tropes, however, which is explaining how they bunch up in coherent ways. Attempts to posit ways to bundle tropes together without adding something new to the mix are unsuccessful (see my old post with a link to work on this topic by Dr. Bill Vallicella). Molnar bites the bullet and admits objects as an additional ontological category. Powers are powers of objects. (Later in the book, though, he will admit ungrounded powers as well).

C. Relations. In Molnar’s assessment, objects are separable from their location in space-time. This leads him to add relations as an additional irreducible ontological category.

Given these ingredients, at least one ontological category Molnar will not need are “states of affairs” (or facts or situations, etc.), which he criticizes in section 2.3.

Still, I think that one can be more economical yet with regard to the size of the ontological zoo. I’ll say more later after a discussion of powers, but I think an event ontology can improve on an object oriented ontology.

Monday, June 11, 2007

Since blogger supports labels now, I created a bunch (which are on the sidebar) and went back and labeled most of the old posts. I'm uploading a photo of my smiling face to stick onto the profile page.

Friday, June 08, 2007

Dr. Carrie Jenkins (homepage; blog; also a TAR contributor) posted a thought-provoking draft paper on a topic I’m interested in – the question of how we acquire modal knowledge. My notes on this paper follow below.

In previous papers, Dr. Jenkins has presented a strategy intended to show how abstract (and seemingly a priori) truths can be real and yet our knowledge of these can grounded in a way friendly to an empiricist (arithmetical truths were used as a paradigm case). To give my massively oversimplifed take on this, Step 1 of her process involves our forming concepts which are seeded by and grounded in sensory input. These concepts take the pieces of world-data and extend them into maps of how the world hangs together. In Step 2, we examine and manipulate these concepts in order to extend our knowledge to what we normally think of as abstract truths. This step 2 seems to have some rationalist tint to it (where did we get this concept examination and extrapolation faculty?), but the whole package is meant to bring the process closer to an earthly explanation, and seems plausible.

But can this analysis be extended to truths regarding possibility and necessity? After all, as Jenkins discusses early in the paper, it certainly seems as if our sensory input is restricted to empirical truth values: the modal status of these truth values appears to have no detectable impact on this input. To put this in terms of the two steps above: when it comes to modal knowledge, Step 1 encompasses some mystery as well. What is it about our knowledge of the natural world which gives us the pieces to form a valid conceptual map of possibility and necessity?

She connects this problem with the issues surrounding the modal rationalist position that conceivability implies possibility. Of special concern for this paper is the basic question of why should we think that conceivability has anything to do with possibility to begin with. For conceivability to be a guide to modality, “our powers of conceiving would have to be attuned to modal fact.” (p.10)

She notes this wouldn’t be a problem if one is an anti-realist about modal truths, then we can just say they are mind dependent and just an artifact of our concepts. But we want to look at the situation facing realists regarding mind-independent modal truths. How can we explain our knowledge of such truths, including the idea that conceivability implies possibility, without invoking a special faculty of rational intuition?

What follows next is a careful review of the steps in her analytical program. She explains her take on what concepts are and how conceptual truths and falsehoods can be derived from an examination of concepts. She discusses how concepts can be grounded empirically, so they accurately represent aspects of the world. Her stance is that if concepts are grounded in this way, then examination of them can lead to conceptual knowledge.

Ok, now back to the key question for this paper: how can modal conceptual knowledge be derived from empirically grounded concepts. The distinguishing step seems to be her suggestion that in gaining empirical knowledge we gain not just atomic empirical facts, but information on the structure (or structural relations) of the actual world, and this structure can ground concepts that can be examined to gain modal knowledge. The easiest examples to work with to illuminate this idea are certain instances of necessary truths.

She uses the example “all vixens are female” to walk through the process by which the concepts (of vixen and female) are grounded empirically, and the relations between the concepts are also accurate reflections of the relations between the real features of the world represented by the concepts. The result being that when we examine the concepts we find that cannot conceive of “all vixens are female” as false; this directs us toward belief in the necessity of the proposition. Because the way we arrived at the belief was grounded in the right way, it is true. (Question: is possibility more difficult -- is it just that everything which isn't determined to be necessary is thus contingent?)

She notes that this epistemological story would need a full metaphysical theory to fill out the question of exactly why the accurate understanding of actual world structural relations leads to knowledge of modal truth, and this goes beyond the scope of the paper. But her epistemological strategy should be compatible with a number of theories.*

The paper continues with discussions of further implications and responses to possible objections. Then, as part of the concluding section, Jenkins returns to the problem raised in the beginning – that it certainly seems as though the empirical truth values can convey no sensory knowledge of modality. She says that despite its initial plausibility, there is no good reason to believe this statement is true, and this becomes clear when one considers the structure of the world, in addition to just atomic facts.

I liked the paper a lot. The richness and detail of discussion throughout (not captured in this summary) built a strong cumulative case for the argument; and the successful application of the previously developed framework to this question of modal truth speaks well for the robustness of Dr. Jenkins’ research program.

*In my case I had this idea that if I posit an ontology where the concrete world is constructed from events which are actualized possibilities, then our knowledge of these events gives us direct acquaintance with possibilities in everything that we learn (I further speculated in this post that modal knowledge gained in this way could actually precede and be constitutive of other abstract knowledge.)

Friday, May 18, 2007

Something is bothering me at the boundary of physics and metaphysics. It seems very likely that a successful theory of quantum gravity will entail that our actual universe is finite. This follows from two considerations. First, in the new theory, the singularities of general relativity will be banished, and the universe will be seen to be grained at the Planck scale. Second, it seems to me that the observable universe can be identified with the actual universe: in what sense should we consider a putative region of the universe beyond the reach of any possible causal contact to be actual? So, it follows that the actual universe is finite.

Now in reading metaphysical papers recently by Ross Cameron and Jonathan Schaffer, (see posts here and here), I was introduced to the argument for the conceivability of “gunk”. Gunk is stuff every part of which has proper parts -- that is, it is infinitely divisible. Now is a world made of gunk conceivable? It seems so. Now, since I have embraced the general stance that conceivability implies possibility, I would have to concede that if the actual world is finite, this is a contingent rather than necessary fact about the world.

For some reason, this just rubs me the wrong way. I don’t like thinking that something as fundamental as the conclusion that our world is finite in extent is just a contingent fact. But given that we are (famously) adept at conceiving infinities, and the strength of my opinion regarding the modal rationalist link between conceivability and possibility, I’m stuck.

The only strategy which I think might work is as follows. I could assert that the conceivability of infinity is grounded by the whole space of possible worlds, and its application to a single possible world is a mistake. The gunky world would itself have to comprise all possible worlds by virtue of its infinite extent. It would itself necessarily constitute the entire modal space, so it couldn’t also be one of the constituents of modal space. Individual possible worlds themselves would be necessarily finite in this scheme.

Tuesday, May 15, 2007

So, how did this party get started? In Programming the Universe (see also priorposts on this topic), Seth Lloyd would like to retell the cosmological story with qubits instead of elementary particles. However, the section of the book (chapter 3) where he does this doesn’t really add much to the standard account. He interprets fluctuations in quantum fields as superpositions of bits whose possible outcomes "0" and "1" represent low and high energy density. The collapse (or decoherence, following Lloyd’s preferred interpretation) of these superpositions creates pockets of high density which can then be the target of gravitational attraction. If you take out the references to bits, his story seems to be the standard cosmological model. If the universe is really a quantum computer, then matter-energy fields (and space-time) would be derived from qubits.

In other words, the real innovation would come if the computational model helps point us toward a theory of quantum gravity. And here, Lloyd does have some ideas. The book has just a few pages on this, but more detail is found in his paper, “A theory of quantum gravity based on quantum computation”. Some impressions from this paper are below (with the caveat that as usual I can’t understand large portions of it).

The idea is that the metric structure of space-time and the behavior of quantum matter fields “are derived from and arise out of an underlying quantum computer. (p.2)”. One starts with the fact a quantum computer can be thought of as a universal theory for discrete quantum mechanics. Quantum computers represent a causal network (=computational history) of interactions – actually superpositions of such networks. These can be represented as a graph, similar to those in causal set theory. Now, for the matter side of things, note that at each vertex of the graph (=logic gate), qubits can be transformed or not. When they are transformed, this is a scattering event. Each computation is a superposition of different computational histories, one for each pattern of scattering events. The events are the matter.

On the gravity side of things, the superpositions of these computational histories will be seen to correspond to a fluctuation of space-time geometry. Lloyd’s strategy is to “embed the computational graph in a space-time manifold by mapping [the computational graph] C into R4 via an embedding mapping E. (pp.6-7)”. He says that if you do this, then general covariance will follow from the fact that the informational flow through the network is independent of the way the computation is embedded in space-time. The next step (which seems to be the key part of the paper) makes some additional assumptions so that the geometries derived from the computation explicitly obey the Einstein equations (in their discrete Regge calculus form).

Now I can’t follow all the steps here, but what I think he is doing amounts to a demonstration of how a quantum computation could be consistent with the emergence of general relativistic space-time, rather than showing that it would actually do so as a matter of course. He ends up being at least partially circular in invoking our knowledge of the Einstein equations to achieve his explicit results (if someone would like to correct me on this, please do). In contrast, Fotini Markopoulou’s desired ambition (see here and here) is to show that the emergence of space-time is a general consequence of an underlying quantum micro-theory (likewise Olaf Dreyer).

The paper finishes with some ideas on how such a theory would impact a variety of topics in cosmology. For instance, singularities correspond to bits entering or leaving the universe, and black holes do lose information; the model can handle different stages of cosmological evolution, etc. This is interesting stuff, and I’ll be interested in seeing if these ideas are developed further.

Something which intrigues me is how one is supposed to think about this new proposed atom of the universe, the qubit. A practical quantum computer uses properties of familiar particles (spin of an electron or polarization of a photon) as qubits. But if these particles (as well as space-time itself) are derived from these postulated elementary qubits, what are they? Is the superposed atomic qubit just a pure possibility of existence?

[UPDATE: 25 May, 2007. My comments in first paragraph of this post are a bit unfair since later in the book (Ch.8 p.196) Lloyd revisits the story of the history of the universe incorporating some of the ideas from his sections on quantum gravity and complexity. In this discussion, here the computation does indeed have priority status over matter and gravity.]

Monday, April 30, 2007

Seth Lloyd’s book (see prior post) has a nice passage in a chapter subsection entitled “So What?” (p. 168). If the universe can indeed be viewed as a quantum computer, why should we care? He poses this further question: “Do we really need a whole new paradigm for thinking about how the universe operates?” Lloyd says (and it would seem difficult to disagree) that the dominant paradigm of the age of science has been that of universe as mechanism. He proposes a new paradigm: “I suggest thinking about the world not simply as a machine, but as a machine that processes information (p.169 – emphasis original).” In my opinion, however, Lloyd’s discussion, while often suggestive, doesn't really answer the "so what" question. Actually, he underplays how radical and interesting a notion this new paradigm really could be.

Unfortunately, in the section quoted from above, Lloyd doesn’t follow through in offering a philosophically compelling interpretation of this new paradigm. He goes on to discuss how the view might better (technically) account for complexity and how it could help on the quest for a theory of quantum gravity – both topics of subsequent sections. Other statements of this sort sprinkled throughout the book are neutral in tone and vague in terms of what they really mean. Here’s the typical quote: “All physical systems register information, and when they evolve dynamically in time, they transform and process that information. (Prologue, p. xi.)”.

I became frustrated at this: What does it really mean to say physical systems process information? In my own (perhaps uninformed) view of classical computing, the only true information processors are the human beings who provide input, program, and interpret the output. The semantics of information processing are provided by humans exclusively, the rest is syntax. This issue is discussed in one subsection of Lloyds’ book, entitled “Meaning” (p.24), where Lloyd relates being asked by a student: “’But doesn’t information have to mean something?’” The response: “’You’re right that when we think of information we normally associate it with meaning,’ I answered. ‘But the meaning of ‘meaning’ is not clear.’” In the rest of the section (written presumably after some reflection on this), he fails to improve on this answer. He discusses how bits can represent information, and then says “the interpreter must provide the meaning.” Note there is nothing innovative or even quantum mechanical about this discussion.

Here’s the unstated radical interpretation of Lloyd’s theory: If physical interactions ubiquitously can be described in terms of information processing, this implies that something we think belongs uniquely to human (and some animal) agents is also a feature of more elementary physical systems: that is, possession of semantic properties, or intentionality. If one is unwilling to take this step, that’s fine, but then there is no important difference between the new and the old paradigm when it comes to interpreting how human life and mind can fit into the picture of an otherwise lifeless mechanistic universe.

Postscript: It’s not a coincidence that Lloyd’s approach to the measurement problem of QM is conservative. He believes the decoherent-histories approach is practical and useful enough to de-emphasize worries about foundational interpretation.